88. Merge two ordered arrays

Here are two buttons Non decreasing order Array of arranged integers nums1 and nums2, There are two other integers m and n , respectively nums1 and nums2 The number of elements in .

Would you please Merge nums2 To nums1 in , Make the merged array press Non decreasing order array .

Be careful ： Final , The merged array should not be returned by the function , It's stored in an array nums1 in . In response to this situation ,nums1 The initial length of is m + n, The top m Elements represent the elements that should be merged , after n Elements are 0 , It should be ignored .nums2 The length of is n .

Example 1：

 Input ：nums1 = [1,2,3,0,0,0], m = 3, nums2 = [2,5,6], n = 3
 Output ：[1,2,2,3,5,6]
 explain ： Need merger  [1,2,3]  and  [2,5,6] .
 The combined result is  [1,2,2,3,5,6] , In which, bold italics indicates  nums1  The elements in .

Example 2：

 Input ：nums1 = [1], m = 1, nums2 = [], n = 0
 Output ：[1]
 explain ： Need merger  [1]  and  [] .
 The combined result is  [1] .

Example 3：

 Input ：nums1 = [0], m = 0, nums2 = [1], n = 1
 Output ：[1]
 explain ： The array to be merged is  []  and  [1] .
 The combined result is  [1] .

Be careful , because m = 0 , therefore nums1 No elements in .nums1 The only remaining 0 Just to ensure that the merged results can be successfully stored in nums1 in .

Tips ：

nums1.length == m + n
nums2.length == n
0 <= m, n <= 200
1 <= m + n <= 200
-109 <= nums1[i], nums2[j] <= 109

Method 1 ： Double finger needling

class Solution {
    
public:
    void merge(vector<int>& nums1, int m, vector<int>& nums2, int n) {
    
        int arr[205] = {
    0};
        for (int i = 0, n1 = 0, n2 = 0; i < m + n; i++){
    
            if (n1 == m) arr[i] = nums2[n2++];
            else if(n2 == n) arr[i] = nums1[n1++];
            else if (nums1[n1] < nums2[n2]) arr[i] = nums1[n1++];
            else arr[i] = nums2[n2++];
        }
        for (int i = 0, j = 0; i < m + n; i++) {
    
            nums1[i] = arr[j++];
        }  
    }
};

Method 2 ：sort Sort

class Solution {
    
public:
    void merge(vector<int>& nums1, int m, vector<int>& nums2, int n) {
    
        for (int i = 0; i < n; i++) {
    
            nums1[m + i] = nums2[i];
        }
        sort(nums1.begin(), nums1.end());
    }
};